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DTUK0813

April 1-7, 201320 Endo Tribune United Kingdom Edition * Source: GfK and SDM market data 2010 for LuxaCore The Nr.1 in Germany and USA!* No other core build-up material comes closer to the natural properties of dentine than the new LuxaCore Z-Dual: This premium composite for core build-ups and post cementations cuts like dentine. LuxaCore Z-Dual is the first material of its category that combines true DMG-patented nano technology and zirconium dioxide. With LuxaPost, the new glass fiber reinforced and pre- silanized composite post, DMG offers the perfect partner for LuxaCore Z-Dual. www.dmg-dental.com Yet even closer to nature – LuxaCore Z. AZ_LxCZ_DEP_1201.indd 1 24.07.12 17:07 zone is essential for the success of each endodontic treatment. An over instrumentation beyond the apical limit with wide tapered NiTi files always results in apical zip- ping20 , over obturation with apical transgression and a defect in the three-dimensional sealing 21 . Thistypeofcomplicationduring theoperationoftenleadstothefail- ure of the endodontic treatment, particularly in case of a preopera- tive, periapical radiolucency 22 . Expert opinions differ consid- erably concerning the perfect di- ameter and taper for the prepara- tion of the last apical third. A circular preparation of the constriction or an apical limit prepared with a diameter of 40/100mm and a .06 taper is not “cleaner” than a preparation with a diameter of 20/100mm and a .08 taper 23 . However, the precise determi- nation of the apical limit and its verification during the operation are vital for a successful endodon- tic treatment 25 . The working length actu- ally evolves during the root canal preparation due to the instru- ment’s linear action 24 . Protocol The One Shape® method helps to carry out a safe root canal prepa- ration provided that the simple protocol is applied. As for all the root canal preparation methods the pulp chamber opening has to be sufficient for a direct access to the canal system. Dentin over- hangs have to be eliminated. The real challenge in endodontics is to locate the canal path, make it per- meable and secure it down to the working length 26 . The exploration of the root canal is accomplished by using either a MMC 15 type manual file or mechanized instruments such as G-Files® 12/100mm or/ and 17/100mm. In the case of a strongly curved canal path, the coronal part of the canal has to be widened and straightened by us- ing EndoFlare®. This procedure also restricts the bending stress on the instrument during the prepa- ration of the canal’s most api- cal portion 28 . After validation of the exploration process, the pulp chamber has to be thoroughly ir- rigated using sodium hypochlorite (three per cent to 5.25 per cent). The action of the One Shape® instrumentstartswithadownward movement of a few millimetres into the canal at a rotational speed of 400 rpm. As soon as a resist- ance is encountered, a low range up and down movement has to be carried out. This brushing move- ment on the canal walls facili- tates the access to the apical third. To accurately measure work- ing length and achieve apical pa- tency, a thin diameter file connect- ed to an electronic apex locater will guarantee maximum preci- sion. This determination method of the apical limit after enlarge- ment of the coronal 2/3 yields reliable and reproducible results, particularly in long and curved canals29 . As a matter of fact, the working length varies significant- ly during root canal shaping. AMMC15fileretracesthecanal path, frees the foramen from any obstruction and activates the irri- gation solution 30 . This verification of the apical anatomy is particular- ly important when using a single instrument method, since over in- strumentation leads to significant post-operative symptomatology 31 . The use of an electronic apex locator is highly recommended 32 , especially regarding their current precision after elimination of con- straints in the coronal third 33 . Conclusion One Shape® – the single file sys- tem for root canal shaping – is a solution destined to practitioners who face the following difficulties: • reluctance to adopt new tech- niques • aseptic chain organisation • insufficient and inadequate root canal preparation • appearance of overhangs and constraints • mechanised instrument separa- tion • complex instrumental protocol • long and difficult shaping. DT page 19DTß Fig 3